As known, computers such as desktop computer (e.g., personal computers) or notebook computers become essential tools in our daily lives. Moreover, keyboards are important input devices of computers. Via the keyboards, users can input characters or perform control operations. Generally, a keyboard comprises plural keys. These keys are located at specified positions. Moreover, many electronic devices or electrical operation devices are equipped with keys that are used as operation interfaces of performing various designated functions.
For allowing users to perform the input and control operations, the keys of the keyboard are specially designed. That is, in response to a single depressing action, the key is returned to its original position and a triggering signal is generated in response to the depressing action. As for the conventional keyboards, the keys are classified according to the types of the switches in the keys. For example, the keys are classified into some types, including mechanical keys, membrane keys, conductive rubber keys and contactless electrostatic capacitive keys. The use lives, tactile feels and fabricating cost for different types of keys are usually different.
With increasing development of science and technology, the trends of designing electronic devices are toward light weightiness and slimness. That is, the thickness of the key of the electronic device is gradually reduced. However, for providing the position-returning function, the overall volume of the conventional key is still large. Moreover, the conventional key has some drawbacks such as the stuck key problem, the impaired tactile feel or the high fabricating cost. For solving these drawbacks, a magnetic type keyboard with magnetic keys is introduced into the market. The magnetic keys can be applied to the slim-type electronic devices. Moreover, the magnetic keys can provide special depressing feels to users. For example, the associated technologies are disclosed in Chinese utility model patent Nos. CN103065846 and CN204204708.
The structure features and position-returning principles of the magnetic key of the conventional magnetic type keyboard will be described as follows. At least two magnets are located at two opposite sides of an outer periphery of a keycap, and at least two magnets are formed on a keyboard frame at the positions corresponding to the magnets on the outer periphery of the keycap in the vertical direction. Since the magnets on the outer periphery of the keycap and the magnets on the keyboard frame are magnetically attracted by each other in the vertical direction, the keycap can be returned to its original position after the keycap is depressed. The magnetic attraction force generated by these magnets is in parallel with the direction of depressing the keycap. Moreover, the magnetic attraction between two magnets can be replaced by the magnetic attraction between a magnet and a paramagnetic material.
Since the keycap of the key is depressed in the vertical direction, it is necessary to reserve a proper space between the keycap and the keyboard base so as to accommodate the depressed keycap. As mentioned above, the magnetic key of the conventional magnetic type keyboard is equipped with magnets on the outer periphery of the keycap magnets on the keyboard frame along the direction of depressing the keycap. Moreover, the buffering space for accommodating the depressed keycap is required. In other words, the overall thickness and volume of the key structure are very large. The large thickness and volume of the key structure are detrimental to the slimness of the keyboard or the electronic device.